PseudohypoparathyroidismPhase 2NCT04240821
Theophylline for Treatment of Pseudohypoparathyroidism
A Phase 2 study testing Theophylline ER in people with Pseudohypoparathyroidism and Pseudohypoparathyroidism Type 1a, run by Jaclyn Tamaroff at 1 site in United States.
Trial summary
Pseudohypoparathyroidism is a genetic disorder with limited treatment options, characterized by early-onset obesity, short stature, hormone resistance and cognitive impairment. This phase 2 clinical trial will test the efficacy of theophylline, a phosphodiesterase inhibitor, in pseudohypoparathyroidism. Read more about this study
- Who is it for?
- Ages 2 to 99 yearsHealthy volunteers can take part
- Conditions the study is for
- Pseudohypoparathyroidism, Pseudohypoparathyroidism Type 1a, Albright Hereditary Osteodystrophy
- What is being tested?
- Theophylline ER
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 34 participants
- Where
- 1 siteUnited States
- Study dates
- 22 May 2020to 31 Dec 2026
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 99 years
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- 1. Successful completion of the randomized clinical trial "Phase 2 Study of Theophylline Treatment of Pseudohypoparathyroidism IND 133103 (11/1/2016)".
Who cannot join
- History of a seizure disorder unrelated to hypocalcemia
- History of a cardiac arrhythmia (not including bradycardia)
- Hepatic insufficiency including cirrhosis and acute hepatitis (AST or ALT >3x upper limit of normal)
- Congestive heart failure
- Current cigarette use or alcohol abuse
- Pregnancy or intention to become pregnant during the next year
Show all 10Show fewer
- Active peptic ulcer disease
- Current use of medications known to effect theophylline levels
- History of hypersensitivity to theophylline or other medication components
- Unable to comply with study procedures in the opinion of the investigator
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Vanderbilt University Medical Center
Nashville, Tennessee, 37212
About this study
Official title: Open-Label Extension Study of Theophylline for Treatment of Pseudohypoparathyroidism
Pseudohypoparathyroidism is a genetic disorder with limited treatment options, characterized by early-onset obesity, short stature, hormone resistance and cognitive impairment. This phase 2 clinical trial will test the efficacy of theophylline, a phosphodiesterase inhibitor, in pseudohypoparathyroidism. We hypothesize that theophylline will cause weight loss, improve glucose tolerance and decrease hormone resistance in children and young adults.
Read the detailed description
Trial Objectives
- The primary objective of this study is to evaluate the long-term safety of theophylline in patients with PHP.
- The secondary objectives of this study are to evaluate changes in BMI, hormone resistance and epiphyseal closure associated with theophylline treatment of patients with PHP.
Study Design The proposed study is a single center, 24-month open label extension clinical trial for patients with PHP who complete the randomized clinical trial.
- Conditions
- Pseudohypoparathyroidism, Pseudohypoparathyroidism Type 1a, Albright Hereditary Osteodystrophy
- Being tested
- Theophylline ER
- Medical subject headings
- Pseudohypoparathyroidism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Theophylline ERDrug
Also called Theophylline elixir
Oral theophylline
| Study group | Role | What they receive |
|---|---|---|
| Open-label theophylline | Experimental | Oral theophylline - either once daily capsule or q6h elixir. Receives: Drug: Theophylline ER |
What is being measured
The primary outcome is the main question the study is designed to answer.
Adverse Events
Treatment-emergent adverse events will be compared before and during treatment
Measured: 24 months
Secondary outcomes (1)
BMI
Change in BMI
Measured: 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jan 2020
- Study start22 May 2020
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PseudohypoparathyroidismStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is an open-label extension study
- Masking
- None (open label)
- Enrolment
- 34 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Jaclyn Tamaroff
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Jaclyn Tamaroff, Vanderbilt University Medical Center
- Investigators
- Jaclyn Tamaroff, MD, Principal investigator, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04240821
- Sponsor's protocol ID
- IND 133013 Extension Study
- Status last verified
- Feb 2026
- First submitted
- 21 Jan 2020
- Last updated
- 2 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data will be shared upon request
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Open-Label Extension Study of Theophylline for Treatment of Pseudohypoparathyroidism
- ClinicalTrials.gov ID
- NCT04240821
- Acronym / sponsor ID
- IND 133013 Extension Study
- Conditions
- Pseudohypoparathyroidism, Pseudohypoparathyroidism Type 1a, Albright Hereditary Osteodystrophy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 34 participants (estimated)
- Lead sponsor
- Jaclyn TamaroffUniversity, hospital or other
- Study start
- 22 May 2020 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 27 Jan 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Pseudohypoparathyroidism is a genetic disorder with limited treatment options, characterized by early-onset obesity, short stature, hormone resistance and cognitive impairment. This phase 2 clinical trial will test the efficacy of theophylline, a phosphodiesterase inhibitor, in pseudohypoparathyroidism. We hypothesize that theophylline will cause weight loss, improve glucose tolerance and decrease hormone resistance in children and young adults.
Detailed description
Trial Objectives
- The primary objective of this study is to evaluate the long-term safety of theophylline in patients with PHP.
- The secondary objectives of this study are to evaluate changes in BMI, hormone resistance and epiphyseal closure associated with theophylline treatment of patients with PHP.
Study Design The proposed study is a single center, 24-month open label extension clinical trial for patients with PHP who complete the randomized clinical trial.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is an open-label extension study
| Arm | Type | Receives |
|---|---|---|
| Open-label theophylline | Experimental | Drug: Theophylline EROral theophylline - either once daily capsule or q6h elixir. |
Who may qualify
- Ages
- 2 to 99 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- 1. Successful completion of the randomized clinical trial "Phase 2 Study of Theophylline Treatment of Pseudohypoparathyroidism IND 133103 (11/1/2016)".
Key exclusion criteria (10 listed)
- History of a seizure disorder unrelated to hypocalcemia
- History of a cardiac arrhythmia (not including bradycardia)
- Hepatic insufficiency including cirrhosis and acute hepatitis (AST or ALT >3x upper limit of normal)
- Congestive heart failure
- Current cigarette use or alcohol abuse
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Theophylline ERAlso: Theophylline elixirOral theophylline | Drug | Open-label theophylline |
Primary outcome
Adverse Events
Time frame: 24 months
Treatment-emergent adverse events will be compared before and during treatment
1 secondary outcome
BMI
Time frame: 24 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2026.
- Research Group Facebook PageLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Data will be shared upon request
Related trials for Pseudohypoparathyroidism
RecruitingObservational study
Natural History Study of Parathyroid Disorders
Parathyroid Cancer, Primary Hyperparathyroidism
RecruitingObservational study
German Hypoparathyroidism Registry
Hypoparathyroidism, Pseudohypoparathyroidism
Active, not recruitingPhase 2
Theophylline Treatment for Pseudohypoparathyroidism
Pseudohypoparathyroidism, Albright Hereditary Osteodystrophy
Enrolling by invitationPhase 2
Setmelanotide to Treat Obesity in a Patient With Pseudohypoparathyroidism Type 1a (PHP1a)
Pseudohypoparathyroidism Type 1a, Obesity
Active, not recruiting
Albright Hereditary Osteodystrophy: Natural History, Growth, and Cognitive/Behavioral Assessments
Pseudohypoparathyroidism Type 1A, Albright Hereditary Osteodystrophy
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jaclyn Tamaroff, MD principal investigator
Vanderbilt University Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Theophylline ER in people with Pseudohypoparathyroidism and Pseudohypoparathyroidism Type 1a, run by Jaclyn Tamaroff at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 2 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Adverse Events (time frame: 24 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2026.